Dihydrogen in cation-substituted zeolites X - an inelastic neutron scattering study

Research output: Contribution to journalArticle

Authors

  • AJ Ramirez-Cuesta
  • PCH Mitchell
  • DK Ross
  • PA Georgiev
  • HW Langmi

Colleges, School and Institutes

Abstract

An inelastic neutron scattering (INS) study of the rotational - vibrational spectrum of dihydrogen sorbed by zeolite X having substituted sodium, calcium and zinc cations is reported. The rotational - vibrational spectrum of H-2 was observed at low energy transfer ( below ca. 25 meV, 202 cm(-1)); the vibration was that of the H-2 molecule against the binding site (H-2 - X, not H - H). The vibration frequency was proportional to the polarising power of the cation (Na+ <Ca2+ <Zn2+). Polarisation of the H-2 molecule dominated the interaction of H-2 with this binding site. The total scattering intensity was proportional to the dihydrogen dose. However the vibrational intensities became constant at ca. 0.3 wt% showing that the H-2 binding sites had saturated. Additional dihydrogen appeared as unbound or weakly bound dihydrogen exhibiting recoil.

Details

Original languageEnglish
Pages (from-to)2533-2539
Number of pages7
JournalJournal of Materials Chemistry
Volume17
Issue number24
Publication statusPublished - 1 Jan 2007